Ubuntu 14.04 x64
- Open the file (look at the left 3D view)
- There're two objects and an armature. The plane of the top "A" is parented to the bone. Move the bone, the objects moves.
- Select the plane "B", down the bone. Parent to the bone: the plane "A" changes its location with no reason, you can see in the right 3D view.
I don't know why this is happening. Both objects have no modifiers, no vertex groups, applied rot-scale, armature with default loc-rot-scale.
I didn't make this file from scratch, but I cleaned my file to make it almost as a new scene.